(a) Technical Field
The present disclosure relates to a polypropylene resin composition and a molded product thereof.
(b) Background Art
The reduction in weight of automobiles has recently become an issue which is not to be ignored, but needs to be essentially solved due to the environmental regulations, improvement in fuel efficiency, and the like. In the case of a bumper which has the highest weight among all automobile plastic parts, by making the thickness of an injection object small to reduce the weight, the reduction in weight may be achieved and the reduction in costs and the productivity may be improved. At this time, the thickness of an injection product may be decreased by adjusting the fluidity of a resin composition, but when the thickness of the injection product is small, mechanical properties deteriorate with the thickness reduction, and accordingly, there may occur problems in that the assembling workability on automobile production lines, the stability of the vehicle, and the safety of passengers in the vehicle in the case of an accident decreases. Thus, the rigidity and the like may be reinforced by using a highly rigid inorganic filler such as long fiber and carbon fiber, but in this case, there may occur a problem in that the appearance is not uniform and the dimensional stability deteriorates during molding.
When injection molding is performed, a plurality of periodic striped patterns called flow marks or tiger marks occur on the surface of an injection molded product in a direction crossing with the direction of flow. In particular, when a large molded product such as an automobile bumper is injection-molded, as the flow length is elongated, striped patterned appearance defects called flow marks easily occur near the end of the flow. When flow marks occurring on the surface of a molded product are conspicuous, the appearance of the molded product is damaged.
Therefore, in order to secure the stability and safety in the case of an accident while lowering energy consumption required for injection molding, there is a need for developing a material itself, which has high fluidity and rigidity for an ultra-thin film of a part, and does not generate flow marks.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.